said Tuesday it was dropping out of a partnership with the Dutch company
to develop and market a treatment for schizophrenia.
The two companies said in a terse statement that Pfizer will return "all product rights, intellectual property and data to Organon and make orderly transitions during 2007."
Pfizer's decision to quit the program "is an outcome of a commercial analysis of the compound as a part of its overall portfolio," the statement said.
Organon said it will continue to develop the drug asenapine. Organon is the pharmaceutical division of
, a drug and chemical conglomerate.
Last month, Organon said it might delay seeking approval for asenapine from the Food and Drug Administration because clinical trial results were "mixed." Organon had hoped to file an application for asenapine's clearance in early 2007, but it said the process might need more time as the company delivers added data to the FDA.
Three years ago, Pfizer agreed to pay Organon $100 million upfront and as much as $270 million in milestone payments in order to take part in the program.
Pfizer's decision to end its participation marks the second time in five months that it walked away from a development deal. In June, Pfizer cancelled its agreement with
to market the insomnia drug Indiplon.
The companies had signed an agreement in 2002, but Pfizer called off the arrangement a week after Neurocrine said it would need to conduct additional clinical trials for a long-acting version of Indiplon and might require more studies for an immediate-release version of the pill.
Pfizer had been counting on the Neurocrine and Organon drugs to diversify its product portfolio and help offset the impact of generic competition to its big-selling products.
On Thursday, Pfizer will discuss its R&D efforts with analysts and investors, providing an update on the clinical progress of its best-known experimental drugs and perhaps disclosing details on compounds in earlier stages of development.